The present invention relates to electronic parking meters and in particular to parking meters which can also be used as an electric car battery recharging station capable of providing various power levels depending on the requirements of the electric car batteries to be recharged.
Automobile battery charging has generally been accomplished using small portable charging devices. Such devices include small portable chargers commonly seen in automobile parts stores and gas stations, as well as generators and alternators driven by internal combustion engines. With the advent of electric automobiles, the requirements for such chargers has changed drastically. The number and size of batteries required for electric cars renders charging by standard methods unrealistic because of the amount of time required and the unavailability of convenient recharging stations. The result has been a new generation of chargers which have different power requirements and capacities.
These new chargers are sometimes mounted in the electric automobile itself. When an owner of the electric automobile needs to recharge the batteries, he drives the car into his garage and plugs the onboard charger into the household electric current. Generally, such chargers take several hours to recharge electric automobile batteries with the time required related directly to the current and voltage available to the batteries. Since it is necessary to match current requirements and charging voltage to the vehicle batteries for the most efficient charging mode, chargers generally have one or more step-up or step-down transformers included in their circuitry. If one desired to increase charging speed, it would necessitate larger voltages and currents, with resultant larger transformers and related circuitry. Since electric automobiles are sensitive to weight, and since larger transformers are generally quite heavy, it is unlikely such increased capacity chargers will be placed in the electric vehicle.
Currently, power available to recharge vehicles is restricted to the owner's home or possibly the owner's office. Since electric automobiles using current technology have to be recharged every 75-200 miles of operation, a problem exists which severely limits the realistic use of electric automobiles.
Public availability of recharging facilities and power sources simply does not exist.